You can get the results in about 15 minutes and the antigen tests are significantly easier to manufacture. They make it more feasible to produce enough to be able to test significantly more people.

But the speed and simplicity do come with a tradeoff in terms of accuracy. The Food and Drug Administration issued an emergency use authorization for the new antigen test created by Quidel.

The test still uses a swab to collect the sample. So what makes it so different?

All of the previous tests for active COVID-19 infections are what we call PCR tests. That means they are looking for genetic material from the coronavirus and multiplying that material until there is enough to detect it.

The antigen test is looking for something different, pieces of surface proteins from the virus, usually the spikes that are big enough to detect without multiplying them.

Last month on Meet the Press, Dr. Deborah Birx called for this type of testing breakthrough.

“We have to be able to detect antigens, rather than constantly trying to detect the actual live virus or the viral particles itself,” said Birx.

There is a downside to antigen tests. They have a higher rate of false negatives. That means if you test positive, you can be confident that’s an accurate result.

But if you’re negative, there is a lower degree of certainty and your doctor may want to confirm that result with a PCR test, especially if you are showing symptoms.

Remember, there is no perfect test. That’s why we need other measures like masks, social distancing, and handwashing too.

This is the first antigen test to be authorized, but it won’t be the last. The FDA says it expects antigen tests to play a critical role moving forward.